ASK AN EXPERT

Got a question about a health story in the news or a health topic? Here's your chance to get an answer. Send us your questions about general health topics, diet and fitness and mental health. If your question is chosen, it could be featured on CNN.com's health page with an answer from one of our health experts, or by a participant in the CNNhealth community.

Name*Location*Email*Question*

* CNN encourages you to contribute a question. By submitting a question, you agree to the following terms found below.

Select a topic? (optional)

You may not post any unlawful, threatening, libelous, defamatory, obscene, pornographic or other material that would violate the law. By submitting your question, you hereby give CNN the right, but not the obligation, to post, air, edit, exhibit, telecast, cablecast, webcast, re-use, publish, reproduce, use, license, print, distribute or otherwise use your questions(s) and accompanying personal identifying and other information you provide via all forms of media now known or hereafter devised, worldwide, in perpetuity. CNN Privacy Statment.

Thank you for your question!

It will be reviewed and considered for posting on CNNHealth.com. Questions and comments are moderated by CNN and will not appear until after they have been reviewed and approved. Unfortunately, because of the voume of questions we receive, not all can be posted.

Expert Q&A

Is secondhand smoke really that risky?

Asked by David, Tampa, Florida

Really, how much secondhand smoke does a nonsmoker get anyway? If a person who smokes a pack a day for 30 years is only 1/3 more likely to die younger than a nonsmoker, then how likely is it that a nonsmoker is even more likely to die younger merely because other people smoke?

Expert answer

Dear David,

I have to say I disagree with some of your risk assumptions. Smoking is always to be discouraged. I can think of no epidemic as devastating and preventable as that caused by tobacco consumption. Tobacco is the only product that I can think of that, when used as intended, causes premature death to at least half of its users. Smoking causes lung cancer, at least a dozen other cancers, as well as cardiovascular disease and lung disease.

Secondhand smoke, which is also called environmental tobacco smoke, is smoke inhaled involuntarily.

Secondhand smoke also causes lung cancer, heart and lung disease in non-smokers. There is no safe level of exposure, but long-term exposure increases risk of lung cancer by 10% to 15% and heart disease by 30%. This translates into 5,000 to 10,000 lung cancer deaths and 40,000 heart disease deaths each year in the United States. Worldwide, it is estimated that exposure to secondhand smoke caused 50,000 lung cancer deaths and 379,000 heart disease deaths in 2004.

Components of tobacco smoke such as carbon monoxide, nicotine, benzene and small particles can easily be measured in the air of a smoker's home or workplace. It is truly a form of indoor air pollution. These smoke byproducts can be measured in the blood and urine of nonsmokers exposed to them. This means they inhaled the byproducts and the byproducts got into their body.

Someone who is around a smoker inhales more benzene, a cause of leukemia, than he or she would inhale spending the same amount of time filling a car with gasoline.

We worry about exposure of children and especially young children who cannot get away from adult parents who smoke. Children are also destined to long-term secondhand smoke exposure. Secondhand smoke exposure causes eye irritation, asthma and other acute respiratory diseases and is thought to be a cause of infant crib death.

The initial studies showing that secondhand smoke is dangerous compared nonsmoking spouses of smokers with age-matched nonsmoking controls who were married to nonsmokers. The spouses of the smokers had a significantly higher risk of lung cancer. Also, a study of nonsmoking flight attendants who worked when smoking was allowed on aircraft had higher lung cancer rates than nonsmoking airline employees who did not work onboard. The tight confines of the airplane gave them especially heavy doses of secondhand smoke.

Numerous studies of secondhand smoke have been completed over the past 40 years. A meta-analysis of 52 studies prepared for the 2006 Surgeon General's Report on Smoking and Health showed that nonsmokers who had long-term (more than 20 years) exposure to secondhand smoke were 1.21 times more likely to develop lung cancer compared with nonsmokers who were never exposed to secondhand smoke.

A second meta-analysis of 25 studies showed that nonsmokers who are exposed to secondhand smoke were 20% more likely to develop lung cancer compared with nonsmokers working in a smoke-free environment.

Interestingly, the biggest benefit from limiting secondhand smoke is from reduction in cardiac disease. It has been demonstrated several times that towns initiating laws limiting public and workplace smoking see in a decrease in heart attack rates within one year of enacting the laws.

CNN Comment Policy: CNN encourages you to add a comment to this discussion. You may not post any unlawful, threatening, defamatory, obscene, pornographic or other material that would violate the law. All comments should be relevant to the topic and remain respectful of other authors and commenters. You are solely responsible for your own comments, the consequences of posting those comments, and the consequences of any reliance by you on the comments of others. By submitting your comment, you hereby give CNN the right, but not the obligation, to post, air, edit, exhibit, telecast, cablecast, webcast, re-use, publish, reproduce, use, license, print, distribute or otherwise use your comment(s) and accompanying personal identifying and other information you provide via all forms of media now known or hereafter devised, worldwide, in perpetuity. CNN Privacy Statement.

The information contained on this page does not and is not intended to convey medical advice. CNN is not responsible for any actions or inaction on your part based on the information that is presented here. Please consult a physician or medical professional for personal medical advice or treatment.